1. Field of Invention
The present invention relates generally to conveyor chutes and more particularly to improved terminal concrete discharge chute sections sized and shaped to cause concrete to be unloaded at an angle to the remainder of the truck chute, as, for example, when the conveyor chute of a ready mix concrete truck is located at an acute angle less than 90 degrees in respect to a concrete form where the concrete is to be deposited.
2. Prior Art
Gravity flow conveyor chutes used in delivering concrete on a job from a ready mix truck typically comprise a series of linear U-shaped sections, about four feet long, which are hooked together. Both the proximal and distal ends of each section are perpendicular to the longitudinal axis of the section. The mentioned sections attach to a similarly shaped starter chute section that is pivotable though integral with the ready mix truck. However, the starter chute section is, normally, wider and deeper at the proximal end where the concrete from the mixer enters the truck chute.
The linear chute system works well enough in many applications; however, often it is necessary to pour concrete into a narrow vertical form or the like to construct a foundation, etc. To avoid excessive delays and prevent loss of concrete, the chute must be positioned at or very near a right angle to the concrete form. Often, the nature of the construction site, the existence of excavation stored randomly, the nature of the opening where the concrete is being placed, the softness of the adjacent terrain, etc., dictate or make advisable placement of the ready mix truck conveyor chute at an angle less than 90 degrees to the concrete form. Under these conditions, discharge from the standard conventional perpendicular-ended chute burdensomely requires the constant attention of one or more workers to avoid loss of expensive concrete and expenditure of an excessive amount of time for the proper placement of the concrete in the form. In fact, under even the best of conditions at the site of a typical foundation pour, the necessity for the truck to move around the perimeter of the foundation while discharging concrete to fill the forms up to grade level makes it advisable that the conveyor chute be positioned at an angle of less than 90 degrees in relation to the forms in order to be able to compensate for changes in the distance from the truck to the forms by manually rotating the chute.
Although the concrete industry has been well established for many decades, no one has advanced a practical solution to the above mentioned problem. The proposed solution found in U.S. Pat. No. 3,746,140 is the antithesis of the present invention and requires a flexible tubular discharge member 50 which is caused to hang within or above the concrete form where concrete is being poured. Utilization of a flexible tube as suggested by U.S. Pat. No. 3,746,140 is objectionable since the flexible discharge tube will tend to cause the aggregate within the fluid concrete to segregate. Thus, the resulting concrete article (foundation, etc.) will lack homogenity and strength. Spalling in response to wetting and drying and freezing and thawing often occurs. In addition, the tubular discharge member limits the rate at which concrete is poured and has a very restricted useful life, due to the wear and stress imposed by the concrete passing through the tubular discharge member. Furthermore, the tubular discharge member must be disposed substantially immediately above the concrete form and has no capacity to provide for additional horizontal displacement of the concrete per se.